03Heat remaining oil in a saucepan, add garlic and onion, cook until soft and add tomatoes. Simmer gently about 10 minutes. Season with salt and pepper and set aside.04Preheat oven to 450 degrees. Use a little remaining butter to grease a shallow baking dish about 9 by 13 inches. Use a 2- to 3-inch round cookie cutter or a glass to cut disks of chilled dough. Keep dipping cutter in cold water to prevent sticking. Lift disks off baking sheet and arrange, slightly overlapping, in baking dish. Scraps can be kneaded briefly and smoothed out to allow for a few additional disks. Sprinkle disks in dish with remaining cheese and dot with remaining butter. Bake about 15 minutes, until lightly browned.05Gently reheat sauce. Serve gnocchi with some sauce alongside each portion.